Process of making phonographic records



Patented 0st.,- 19, 1926.,

' NETE@ STATES @FFHCEQ WILLIS O. PROUTY, 0F HERMOSA BEACH, CALIFORNIA, AND VALTER A. SCOTT, 01E' v RIVER FOREST, ILLINOXS.

PROCESS OF MAKNG PHONOGRPHC RECORDS.

Application filed March 25, 1926. Serial No. 97,327.

ylhe purpose of our invention is the provision of means for making phonographic records in the form of long-strips or tapes with the record extending longitudinally thereof, the material of the strip or tape suiiciently flexible to be wound on a reel. The fact that a flexible tape would afford means for making phonographic records of great length has been perceived heretofore, but the production of such a record involves difficulties not encountered in the production of the disc records now used. We haveinvented a simple and economical method of producing such 'records In brief we' first make a record in a helical line upon the outer surface of a hollow, thin cylinder of celluloid or material having similar properties. The pitch of the helix which the record follows is made suiiciently great to leave a substantial space between successive turns of the record line. After the completion of the cylindrical record we cut the record along a helical-line, the line of the cut running between the successive turns of the previously formed record line, thus producing the record in the form of a strip the length of which is dependent only on the diameter and length of the cylinder upon which it was originally produced. instead of producing a single record line upon the strip or tape a plurality of record lines may be formed side by side and comparatively close together, the pitch of the helical path of the record lines being suiilciently great to leave suiicient cutting space beween the successive turns of the group of record lines.

In the drawing: l

liligure 1 is a side view of a hollow cylinder of celluloid or material of similar properties having two record linesn helical form indicated thereon, and the intervening cutting lines also shown.

Figure 2 is a view of a section of the strip or tape formed by cutting the cylindrical record shown in Figure l along a helical line.

`Methods have` heretofore been devised and used to a considerable extent wherein thin, hollow cylindrical records have been formed by'expanding a hollow celluloid cylinder, or cylinder of some similar material, within a hollow cylindrical matrix bearing the phonographic record'on its inner surface. These matrices have been formed by electro-deposition of metal upon the surface of a. cylindrical wax record and then backing the thin electro-deposit with a substantial layer oi metal. rllhis part of the procedure is old and forms no part'of our invention, nor does the procedure followed in expanding the blank celluloid cylinder within the matrix to impress the record thereon. A method heretofore used Jfor expanding the celluloid cylinder the matrix consists in closing the ends of the cylinder steam-tight while in position within the matrix and then injecting into the interior of the cylinder steam under suiiicient pressure to produce the desired result. The heat 'of the steam softens the materialsuiiiciently to cause it to receive from the'matrix the impression of the record and the pressure causes the outer surface of the cylinder` to establish such intimate contact with the matrix that the impression of the record isvan exact reproduction. Upon cooling, thev cylinder contracts suciently to permit its withdrawal from the matrix. The details of this part of the procedure beingold need not be further described here.

In Figure l' we show a cylinder hearing: l'

two record lines side by' side, which lines may represent either se arate recordsbr successive parts of a sing e record to be reproduced continuously by reversing the direction of movement of the tape under the reproducing needle when the end of the tape is reached. 'lhis cylinder may be /formed by the procedure above referred to or by anyxother suitable method such as flowing a temporarily liquefied material over the interior of a hollow cylindrical matrix. After being so formed the thin cylindrical record is cuit along the helical line indicated b the` numeral 3, thus converting the recor ,into the form of the tape showny in Figure 2l'with the record lines 1, 2 extend ing longitudinallythereof. The above described methods of producing Ithin cylindrical records are applicable to the production of cylinders of large diameter and great length, thereby rendering it possible by our improved method to produce continuous tape records of great length.

We claim; Y,

'1. In a process of the class described the.`

operation of forming a phonographic record in a helical line on the surface of a cylinder and then cutting from said cylinder a helithe helical record line and thereby producing a record in the form ofa strip having 10 the record line extending longitudinally thereof.

In testimony whereof, We have .subscribed 0111 flames.

" WILLIS O. PROUTY.

WALTER A. SCOTT. 

